Understanding Food Insecurity as a Determinant of Health in Pregnancy Within the United States: An Integrative Review

Background: Food insecurity is a major public health concern in the United States, particularly for pregnant and postpartum individuals. In 2020, ∼13.8 million (10.5%) U.S. households experienced food insecurity. However, the association between food security and pregnancy outcomes in the United States is poorly understood. Purpose: The purpose of this review was to critically appraise the state of the evidence related to food insecurity as a determinant of health within the context of pregnancy in the United States. We also explored the relationship between food insecurity and pregnancy outcomes. Methods: PubMed, CINAHL, Web of Science, and Food and Nutrition Science databases were used. The inclusion criteria were peer-reviewed studies about food (in)security, position articles from professional organizations, and policy articles about pregnancy outcomes and breastfeeding practices. Studies conducted outside of the United States and those without an adequate definition of food (in)security were excluded. Neonatal health outcomes were also excluded. Included articles were critically appraised with the STROBE and Critical Appraisal Skills Program checklists. Results: Nineteen studies met the inclusion criteria. Inconsistencies exist in defining and measuring household food (in)security. Pregnant and postpartum people experienced several adverse physiological and psychological outcomes that impact pregnancy compared with those who do not. Intersections between neighborhood conditions and other economic hardships were identified. Findings regarding the impact of food insecurity on breastfeeding behaviors were mixed, but generally food insecurity was not associated with poor breastfeeding outcomes in adjusted models. Conclusion: Inconsistencies in definitions and measures of food security limit definitive conclusions. There is a need for standardizing definitions and measures of food insecurity, as well as a heightened awareness and policy change to alleviate experiences of food insecurity.


Introduction
In 2020, 10.5% (*13.8 million) of households in the United States experienced food insecurity. 1 Of the households with children, the majority are headed by single mothers. 2 Food insecurity, an economic and social condition characterized by the inability or limitation to access adequate food, 3 is particularly important for women of reproductive age.Poor nutritional status can coexist with chronic health conditions, such as cardiovascular disease 4 and type 2 diabetes mellitus, 5 which put individuals at increased risk for obstetrical complications contributing to morbidity and mortality during pregnancy and within the first year postpartum. 6ecognition of the impact of mutable upstream factors, 7 commonly referred to as ''social determinants of health'' (SDOHs), has significantly increased over the past 30 years. 8Economic stability, for example, is an SDOH characterized as the need to help people earn a living wage 9 to carry out basic health needs, which includes the ability to acquire healthy foods.Concerns about accessibility and affordability of quality food in the United States have exacerbated during the COVID-19 pandemic, with the rate of U.S. households with children experiencing food insecurity increasing by 23% 10 during the pandemic compared with the 2018 data. 11trition in pregnancy Nutritional status of individuals before pregnancy is an important contributor to health during pregnancy and the lifecourse.12 For example, preconception bodyweight (both low and high) is associated with poorer pregnancy outcomes.12 Oftentimes, pregnancy is described as a ''critical window'' in women's health, 13 as pregnant individuals are more inclined to adopt behavioral changes.15 Therefore, nutritional education and access to preconception services for women of reproductive age are crucial to setting a foundation for a healthy pregnancy.12 Maintaining adequate nutritional status is vital for maternal well-being.16 Pregnant people are expected to gain a prescribed amount of weight, based on their prepregnancy body mass index (BMI), and return to an ''appropriate'' BMI through lifestyle behaviors 17 within the first year postpartum.However, behavioral interventions largely place responsibility on the individual and do not address environmental factors, such as access to high-quality and nutritious foods, 18 that affect capacity for behavior change. Mot recommendations from the Dietary Guidelines for Americans pertain to the development of the fetus, maternal weight, and lactation goals.There is a gap in the guidelines for postpartum people who are not lactating and for those who may have experienced a metabolic complication in pregnancy, such as gestational diabetes mellitus (GDM).

Purpose
There is a paucity of literature that examines the association between food security and pregnancy outcomes in the United States.The purpose of this integrative review is to (1) critically review the state of the evidence related to food insecurity as a determinant of health within the context of pregnancy in the United States and (2) describe the association of food insecurity as a determinant of pregnancy outcomes.Acknowledging that not all pregnant people will identify as women or mothers, gendered and nongendered terms will be used interchangeably.For context, *5.6% of adults in the United States identify as transgender, 19 a subset of whom are transgender individuals of childbearing age.

Design
This integrative review was guided by the methodologies described by Toronto and Remington. 20To capture the multidisciplinary nature of this topic, literature searches were conducted in the PubMed, CINAHL, Web of Science, and Food and Nutrition Science databases.A health services librarian was consulted to increase specificity of studies. 20Searches took place between March and October 2022.Additional databases and search engines were manually searched to identify potential gray literature and minimize publication bias. 20Table 1 describes the search terms used.

Inclusion and exclusion criteria
The inclusion criteria included research articles published after 2006 and conducted within the United States about food security or insecurity written in English that were peer-reviewed; position articles from professional organizations; or policy articles with a discussion of pregnancy outcomes and breastfeeding practices.Articles that did not contain an adequate explanation or definition of food security or insecurity in relation to pregnancy were excluded.Conference abstracts, editorials, and publications that focused on neonatal health outcomes were also excluded.

Search results
From the initial literature search, 2647 articles were imported into Covidence Systematic Review Software.Eight hundred eighty-two total duplicates were removed, yielding 1765 unique citations for title and abstract screening.Using strict inclusion and exclusion criteria, 147 full-text studies were assessed.Following a full-text review, 19 articles remained and were included for final analysis.Figure 1 presents the search strategy via Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

Data analysis
Data analysis for this review used the constant comparison method. 21Studies were read in chronological order based on publication date.Data extraction was independently conducted by coauthors (V.C.P. and L.G.) using a data matrix.Codes were compared and then regrouped into separate columns with subheadings that described the factors and outcomes associated with food insecurity (Table 2).

Critical appraisal
The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist was used for cross-sectional and cohort studies.The Critical Appraisal Skills Program (CASP) checklist was used to appraise the qualitative studies, supplemented by triangulation (inclusion of multiple data points, sources, and researcher points of view) and reflexivity (awareness of and authenticity about one's own identity, role, and influence within the research context) as defined by Tracy and Hinrichs 22 that are not mentioned in the CASP tool.Table 3 displays strengths and weaknesses of each study using the respective critical appraisal tools.
Sample populations within each study were reflective of the U.S. pregnant population.The samples were diverse in age, race, ethnicity, income, education status, and public and/or private insurance.Included studies were reflective of most geographic regions in the United States.One article specifically described rural communities. 23Four articles were conducted in urban settings. 24,25,31,37Urbanicity was unable to be identified in eight studies as Laraia et al., 2,[27][28][29]36 Dinour et al., 34 and Stevens 39 used state-specific data. Orzco et al. 38 and Park and Eicher-Miller 35 used national data.Research aims in the included studies focused on describing the predictors and prevalence of food insecurity during pregnancy and investigating food insecurity as the predictive variable on several pregnancy complications, such as GDM, 26,29 hypertension, 29,30 and anemia. 35Table 5 provides a summary of the characteristics of the included studies.
The following patterns were identified by pregnant and postpartum people who experience food insecurity: (1) psychological consequences, (2) physiological abnormalities, and (3) maternal hardships and inequities.

Psychological consequences
37,39 The data revealed the following three subcategories: depression, anxiety and stress, and personal disposition issues.
Depression.In three studies, experiencing even marginal food insecurity was associated with developing symptoms of depression. 2,24,36Postpartum women with marginal food insecurity had 1.5 times the odds of having depressive symptoms compared with those in food secure households while controlling for income, race, education, marital status, and number of dependents. 2 Feelings of hopelessness, 37 despair, 23 and lack of control 2 contributed to depression while experiencing food insecurity.The Center for Epidemiological Studies Depression Scale, which is validated to assess for risk of depression in pregnant populations, was used in three of the studies; 2,24,37 however, because symptoms of depression such as changes in appetite or fatigue can be nonpathological characteristics of pregnancy, assessing for depression was described as challenging.
Anxiety and stress.During pregnancy and postpartum, the main contributor to stress and anxiety was feelings of worry in having enough food for their families, particularly for other children in the home. 25,37,39conomic hardships, such as balancing monthly household finances, were considered an additional source of stress 31,39 particularly among low-income communities, regardless of receiving public assistance such as Supplemental Nutrition Assistance Program (SNAP) or Women, Infants, and Children (WIC). 2,28,37,39In a study of food insecurity among adolescents, newly postpartum mothers had to decide whether to pay their rent or provide food for their families, 39 contributing to overall stress.
Personal disposition issues and coping.Three articles described maladaptive behaviors that were associated with having food insecurity. 2,23,37Laraia et al. 2 found that pregnant women experiencing household food insecurity developed a poor sense of self.Pregnant women from food insecure households in this study scored three times lower on the Rosenberg's Self-Esteem Scale used in this study compared with those from food secure households. 2 For context, a low score indicates a less favorable attitude about oneself.There was also a development of loss of control over one's life or that life was controlled by chance. 2 Sullivan et al. 23 had similar findings; 22.4% of food insecure participants felt they had less control over their own life.Smoking, drinking, and illicit drug use were significantly correlated among pregnant people experiencing food insecurity. 23,37However, it is unclear from these two studies if participation in these activities during pregnancy was a result of food insecurity or other life factors.

Physiological abnormalities
[30]35,39 Altered eating patterns and behaviors,  gestational weight gain, pregnancy complications, and breastfeeding changes were identified as subcategories.
Altered eating patterns and behaviors.Minimal food intake or completely skipping meals was described as eating patterns among pregnant research participants. 23,25,27,39Nonhomeostatic eating, described as consuming calorie-dense, non-nutritious foods, was a common eating pattern for food insecure pregnant women. 2,23,27,39Laraia et al. 27 found that eating attitudes and behaviors, such as restricting food due to concerns of weight gain, were poor during pregnancy and worsened postpartum in food insecure groups.
The study reports a sensitivity analysis controlling a portion of the sample that falls at or below 400% of the federally poverty line and results remained statistically significant at the 0.05 level.This shows that there are additional barriers to obtaining nutritious foods that affect behaviors toward eating.
Gestational weight gain.Four studies examined gestational weight gain and food insecurity with conflicting results.8][29] In contrast, Cheu et al. 25 found insufficient weight gain and lower total gestational weight gain ( p < 0.001) associated with food insecurity.Notably, the three studies that found an excess in gestational weight gain were all secondary analysis from the same prospective cohort study.
Pregnancy complications.Some studies demonstrated associations between food insecurity and hyperten-sion during pregnancy, 23,30 second trimester anemia, 35 and GDM. 26,29In an adjusted model used by Laraia et al., 29 the odds of GDM within a food insecure household were 2.38 times the odds of GDM within a food secure household ( p < 0.05).In a cohort study by Sullivan et al., 23 of the participants who had preeclampsia during pregnancy, 29.8% were food insecure compared with 18.4% of those who were food secure ( p = 0.02).
The etiology of hypertension in pregnancy is complex; however, Morales et al. 30 found that participation in a food resource program, which initiated SNAP, WIC, and access to a food pantry, improved overall blood pressure throughout pregnancy compared with those who did not participate.
Breastfeeding.Five studies addressed the effects of food insecurity on breastfeeding.Of these, two studies focused on infant health and breastfeeding as a childhood obesity prevention behavior. 32,4034]38 Studies addressed additional child-specific outcomes, including restrictive and pressured feeding styles, 32 or specific feeding behaviors such as early introduction of solid foods before 4 or 6 months of age 38 or adding cereal to a baby bottle during feeds 32 as a result of food insecurity.None of the included studies investigated positive maternal health outcomes associated with breastfeeding, such as postpartum weight loss, involution promotion, decreased postpartum bleeding, or improvements in glucose metabolism for mothers diagnosed with GDM.Findings associating food insecurity with breastfeeding behaviors were mixed.One study found no significant association between food insecurity and current breastfeeding in a sample of WIC-eligible mother-infant dyads 2 weeks to 6 months postpartum. 32However, Frazier et al. 33 found in adjusted analysis controlling for sociodemographic variables that food insecure mothers were significantly less likely to continue breastfeeding.

Maternal hardships and health inequities
The prevalence of experiencing food insecurity was higher among low-income, single, African American and Hispanic pregnant people in their 20s. 2,25,30ncome was an independent risk factor for food secu-rity concerns. 2,23,39Participation in federal government assistance programs, such as SNAP and WIC, ranged from 30% to 90%. 2,33,34,37,39,40Support from such programs was consistently described as insufficient to support food security. 39When parents decided to feed their infant formula, the assistance was also insufficient, as the monthly stipend decreased. 34Experiencing housing instability 23,30,36,39 was not only associated with food insecurity but also made obtaining support from government assistance programs unattainable, as a permanent address may be required. 40Transportation challenges 31,39 were also associated with food insecurity during pregnancy.Immigrant women noted     the need to financially support family members in their home country as an added stressor that affected their ability to purchase food. 40astly, Laraia et al. 36 found that experiencing marginal, low, and very low food security was significantly associated with lack of practical support and intimate partner violence.

Common strengths and weaknesses
A main weakness among the included articles was a lack of explanation of screening tool modification to address household food security or insecurity in pregnancy. 23,25,30,36,37The studies with modified surveys did not report reliability statistics.The variability in definitions and measurements of food insecurity was a source of ambiguity in the data included in this review.One study described a theoretical framework utilized in the research. 36Clear objectives and significance were a common strength throughout the articles.Statistical analyses were appropriate for most studies.

Discussion
Our findings suggest that pregnant and postpartum people experiencing food insecurity face greater hardship, and worse physiological and psychological outcomes than those who do not.Studies identified a mental health component that suggests food insecure pregnant people are at greater risk for developing depressive symptoms and anxiety.A cumulation of these adverse psychological factors can significantly impact mental health concerns during pregnancy and postpartum.The data suggest that clinical diagnoses of depression may be underreported in pregnant and postpartum people.A small body of evidence shows an association between food insecurity and metabolic complications of pregnancy.For example, Cooper et al. 26 and Lairia et al. 2 found an association between GDM and food insecurity.GDM is known as the most common metabolic disorder in pregnancy 17 and can serve as a catalyst to poor maternal outcomes during birth, 42 postpartum, and throughout the lifecourse. 43efinitions and measurements of food insecurity varied throughout the literature.For example, in 2006, Laraia et al. 2 used the 18-item survey from the USDA, operationalized its outcome as food secure, marginal food security, and food insecurity, and defined food insecurity as ''whenever the availability of nutritionally adequate and safe food, or the ability to acquire foods in a socially acceptable way is limited or uncertain'' (p.177).The most recently published study used a six-item survey that was modified from the original USDA survey, operationalized as fully food secure, marginally food secure, low food security, and very low food security, and described food insecurity as multidimensional and a health risk that has implications across the lifecourse. 36ack of consensus on measuring and operationalizing food insecurity can lead to conflicting results in food security status.For example, ''classifying'' a household as marginally food secure may include questions that were answered negatively that would otherwise lead a household to be classified as food insecure.Understanding the rationale for the choice and adaptation of survey questions would contextualize the result of this review.
Regional differences might have contributed to some conflicting results in pregnancy outcomes described by Cheu et al. 25 and Laraia et al. 27,29 The discrepancy in gestational weight gain may be explained by differences in food environments, such as food deserts and food swamps.][29] Health risks are created and maintained by faulty social systems 44 influenced by structural racism and patriarchal forces.Food insecurity emerged as a result of the ''Hunger in America'' crisis starting in the 1960s, although federal government assistance programs had already existed. 45Federal government assistance programs were originally designed to be temporary ''emergency programs'' to support farm products. 46However, as economic conditions worsened, programs became permanent and ownership of small farm resources transitioned to agribusinesses. 46he USDA is the government agency that provides support for capitalized farms in addition to food and nutrition programs, such as SNAP and WIC.
SNAP and WIC also rely on the USDA for nutrition guidelines and advice; specifically, the Food and Nutrition Service Agency (FNS). 47FNS's mission is to ''increase food security and hunger in partnership with cooperating organizations by providing children and low-income people access to food, a healthy diet, and nutrition education in a manner that supports American Agriculture and inspires public confidence.'' 3However, The Farm Bill, which provides the safety net for SNAP, also serves as the safety net for farmers. 47hile revisions of the Farm Bill have taken place since its initiation, 47 the highest subsidy is primarily for commodity crops, such as corn, wheat, and soy, which are basic ingredients in processed foods 46 and show an association with cardiometabolic conditions in Americans. 48lthough there are benefits to SNAP, there are pitfalls.SNAP relies on the Thrifty Food Plan, one of the four plans designed by the USDA to be nutritionally adequate at a low cost using a benefits formula. 49he formula operates on assumptions of household expenditures, of which 30% is allocated for food.It does not consider time (food preparation), equipment (food utensils and supplies), and knowledge of its recipients.It also does not consider price variation, which can be complicated by geography or disruptions to the supply chain.Pregnant individuals are not eligible for increases in SNAP until after the neonate is born. 2 It should be noted that WIC relies on a separate funding source and receives significantly less than SNAP. 47This history potentially supports findings from Stevens that monthly disbursements are insufficient. 39tudies in this review reported that their samples comprised women, with no data provided on whether more detailed aspects of gender identity were collected.Further exploration of the role of food insecurity among people across the gender spectrum who have the capacity for pregnancy is needed.Only one study included acculturation 37 as a sociodemographic characteristic to describe food insecurity.Therefore, there are likely cultural and ethnic considerations to what food insecurity means to different groups.

Policy
Food insecurity persisted when controlling for public assistance use along with sociodemographic indicators demonstrating that current federal assistance programs do not go far enough in alleviating the burden of food insecurity in pregnant and postpartum people.Given recent inflation due to the COVID-19 pandemic, 10 federal, state, and local governments must reevaluate their nutrition and housing expenditures to ensure that they are doing enough to support recipients, particularly pregnant and postpartum recipients.In addition, lawmakers should consider the pitfalls of the assumptions that household expenditure on food is only 30%.This could potentially mitigate the financial inequities that contribute to food insecurity among pregnant and postpartum people. 23,30,39Finally, inflation on fresh fruits and vegetables compared with the price of processed foods is directly related to farm policies within the USDA. 46Subsidies for fresh fruit and vegetables should be higher than those for soy, wheat, and other commodity crops.

Health services utilization
Screening for household food security at least once during pregnancy is recommended by the American College of Obstetricians and Gynecologists and the American Academy of Pediatrics. 50The USFSS tool asks a series of questions pertaining to food security within the last 12 months.Food insecurity waxes and wanes at different times, 24 and therefore asking at one point in time may not identify all potential risks when considering the trajectory of pregnancy, postpartum, and beyond. 24 possible solution could be to routinely assess food security at prenatal and postpartum visits.However, none of the studies discussed the responsibility of the obstetrical team to screen.Only one study had an established prenatal social needs screening and risk assessment program with identified pathways for social work and care coordination referrals. 31Postpartum social needs were identified in pediatric settings. 31,39n pediatric settings, mothers experienced embarrassment and shame when discussing food concerns. 39oor patient experiences suggest that regular conversations on food insecurity screening could decrease the stigma felt by pregnant and postpartum people and that conversations should occur early in prenatal care, so that they are well-received later in pregnancy and postpartum.Therefore, screening for food insecurity and other SDOHs should be included in primary care settings for all people with the capacity of pregnancy so that appropriate referrals to either government or community programs can be made.
A greater effort needs to be made to meet people where they are in the community to address their food-related needs, for example, a partnership with community-based food gardens 51 that can receive referrals for food insecure individuals and supply fruits and vegetables to those who need it.

Research
Future research should focus on the association between built neighborhood environment, maternal health outcomes, and the lived experiences of pregnant and postpartum women who experience food insecurity.An explanatory mixed-methods design could provide contextual support of barriers to achieving food security and postpartum health.Research of this nature could support the need for policy reform of public assistance programs.Longitudinal studies would explain how food insecurity affects the life span and establish temporal and causal relationships between food insecurity and health outcomes.For example, evaluating the multigenerational impact of breastfeeding behaviors, food insecurity, and maternal health outcomes, in studies that assess food security and its association with breastfeeding behaviors where research could uncover multigenerational findings.

Limitations and strengths
This integrative review has several limitations.First, we only included studies published in the United States and written in English, which limited the overall number of eligible studies.Five of 19 articles used data from the same observational cohort study, with the same primary author, which could have skewed results.It is unclear if rural settings are represented in this review, and therefore, the results may not be generalizable.In addition, due to the scarce representation of Alaska Native/Pacific Islander and native/indigenous participants, this review cannot speak to their unique strengths and adversities.Strengths include two independent data abstractors, support from a health services librarian, and use of critical appraisal.

Conclusion
An interdisciplinary approach to addressing food insecurity in pregnant and postpartum people has the potential to change our communities for women and people of reproductive age.As demonstrated in this review, the significance of food insecurity in pregnancy is multifaceted and should be considered a critical opportunity to address issues in one's overall health.Shortterm solutions involve screening and referrals to community or federal government programs.Longterm solutions include addressing the root causes of food insecurity, such as accessibility and affordability, which requires a collective effort from policy makers, health care providers, and community programs.If not addressed, there are potentially long-term threats to maternal health, both reproductive and beyond.

Table 1 .
Literature search by database

Table 3 .
Critical appraisal Appropriate surveys were selected to answer the research question Selected confounders are well supported with literature Findings were consistent for the general population Not all survey measures listed reliability psychometrics Regression models were run separately due to ''high coefficients,'' this increases the chance of a type I error p-Values set at 0.03 and 0.008 with no explanation for such No mention of bias (continued)

Table 3 .
(Continued) Self-reported weight contributes to social desirability bias Sample size calculation was not justified and may contribute to committing a type I error Laraia et al. (2022) 36 STROBE Secondary analysis of cross-sectional survey Key elements of research problem are indicated and supported Use of theoretical framework is threaded throughout article for clarity Statistical analyses are well explained and displayed in appropriate tables Study sample and missing data are well explained Chance of selection bias: participants with severe maternal hardship may be underrepresented Introduction mentions causal relationship, but this study did not execute that plan Morales et al. (2016) 30 STROBE

Table 4 .
United States Department of Agriculture food security survey(s) Pasha, et al.; Health Equity 2024, 8.1 http://online.liebertpub.com/doi/10.1089/heq.2023.0116 ''(I/we) relied on only a few kinds of low-cost food to feed (my/our) child/the children) because (I was/we were) running out of money to buy food.''Wasthatoften,sometimes,ornevertruefor(you/your household) in the last 12 months?X ''(I/We) couldn't feed (my/our) child/the children) a balanced meal, because (I/we) couldn't afford that.''X''(My/ourchildwas/thechildrenwere)noteatingenough because (I/we) just couldn't afford enough food.''XStage 2 child screener In the last 12 months, since (current month) of last year, did you ever cut the size of (your child's/any of the children's) meals because there wasn't enough money for food?XIn the last 12 months, did (CHILD'S NAME/any of the children) ever skip meals because there wasn't enough money for food?XHow often did this happen-almost every month, some months but not every month, or in only 1 or 2 months?XIn the last 12 months (was your child/were the children) ever hungry but you just couldn't afford more food?XIn the last 12 months, did (your child/any of the children) ever not eat for a whole day because there wasn't enough money for food?X USFSS, U.S. Household Food Security Survey.

Table 5 .
Summary of reviewed studies